The invention relates to an apparatus for storing at least one specimen slide and at least one cassette having a sample, embedded in a sample block, that is to be processed. The apparatus encompasses a cassette magazine in which is arranged at least one cassette having at least one sample block, and a slide magazine in which at least one specimen slide is arranged. The invention further relates to a method for handling multiple cassettes each having at least one sample block having a sample to be processed, and multiple specimen slides.
The apparatus and the method are preferably utilized in histological technology. Histological technology deals with the investigation of tissue samples from patients. The most common method is to embed in paraffin the tissue sample taken from the patient, cut thin sections from the resulting sample blocks using a microtome, mount each thin section onto a specimen slide, stain them in a further process, cover each with a coverslip, and deliver them to a microscope for diagnostic evaluation. Some or all of the individual steps just described are preferably executed automatically. A sample block is delivered to the microtome in a cassette, the sample block being fixedly joined to the cassette and the sample block being held in the microtome by way of the cassette.
It is necessary for the tissue samples to be uniquely identifiable continuously through all the process steps. The intention thereby is to preclude confusion among samples, in order to avoid incorrect allocation of a sample, a thin section, or an investigation result. An incorrect allocation can cause a healthy patient to be considered ill, and an ill patient to be erroneously considered healthy. Medical actions that might be necessary are then omitted or are instituted only after a delay. A further intention is to avoid sample loss. In order to achieve unique identifiability, all cassettes carry a unique identifier. The difficulty lies in also identifying with an identifier the specimen slides on which a thin section of a sample block has been mounted. The identifier on the specimen slide should be uniquely allocatable to the identifier of the cassette from which the sample block was taken. The identifier of the cassette and the identifier of the corresponding specimen slide are preferably identical. Three methods, which will be briefly explained below, can be used to identify the specimen slide.
In the first method, the specimen slides are labeled manually after the thin section has been mounted onto the specimen slide. This manual labeling of course entails considerable susceptibility to error due to confusion. Manual labeling is further problematic because the label must be read later by other persons, and a manual label is more susceptible to error when being read than a mechanical label.
A further possible method involves already labeling the specimen slide before it is delivered to the microtome and thus before the thin sections are mounted. Labeling can be performed manually or mechanically. Transport of the specimen slides to the microtome, and of the cassettes having the sample blocks to the microtome, occurs separately. It is disadvantageous that after a thin section is produced with the use of the microtome, the matching pre-labeled specimen slide must be located from among a plurality of specimen slides. This requires a manual comparison between the specimen slide identifier and the cassette identifier. This manual comparison and manual identification are associated with relatively high complexity.
In the third possible method, the cassettes having the sample blocks are conveyed in a cassette magazine to a microtome. During processing of a sample block, the identifier of the cassette belonging to it is read off. A labeling unit for labeling specimen slides is arranged next to the microtome. Labeling of a specimen slide occurs concurrently with production of a thin section in the microtome: the identifier on the specimen slide corresponds to the identifier read off from the cassette, or can be allocated to that identifier. Any confusion of specimen slides can thereby very largely be precluded, since labeling of the specimen slides takes place concurrently with production of the thin sections, and only that specimen slide is present in the apparatus. A disadvantage of this method is that a labeling unit for labeling specimen slides must be arranged in parallel with each microtome, which results in a considerable cost outlay when there are many microtomes. A large amount of space can also be required as a result.
The document DE 10154843 A1 discloses a method and an apparatus for identifying specimen slides for microtomed tissue samples and for the processing thereof, in which the identifier information pertinent to a slide is automatically sensed while said slide is arranged in the microtome, and an identifier allocated to that identifier is automatically transferred onto at least one specimen slide. At the point in time at which a microtomed tissue sample must be mounted onto a specimen slide, only that specimen slide equipped with the identifier is presented at the microtome workstation.
A magazine having compartments for the reception of cassettes is known from the previously unpublished document DE 10 2007 059392. The magazine has an external housing having an apparatus arranged therein for stepwise advancing of the cassettes from one compartment to the next compartment.
The document DE 20 2004 006265 discloses a microtome for producing thin sections, which encompasses a reading device for coded information applied onto the cassette. The apparatus further encompasses a control device having a computer for the coordination of all functional sequences. With the aid of the reading device, a code arranged on a magazine having compartments can be read out. The magazine serves to receive prepared cassettes. The microtome further encompasses a handling device for controllable removal of a cassette and for positioning on a sample receptacle of the microtome, and for return into the magazine. The reading device can be arranged in the magazine housing or in the handling device.